Quinidine and Verapamil: Drug Interaction Guide

Quick answer: This is a major interaction — avoid combining Quinidine and Verapamil unless specifically directed by your doctor.

Interaction severity: Major — avoid combination

How Quinidine interacts with Verapamil

Both drugs depress cardiac conduction, and verapamil can inhibit P-glycoprotein and CYP3A4 pathways affecting quinidine exposure, increasing risk of hypotension, bradycardia, and arrhythmias.

What you should do

Avoid unless specialist-supervised. Use ECG and blood pressure monitoring if combination therapy is necessary.

Key facts

Severity

Major — avoid combination

Mechanism

Both drugs depress cardiac conduction, and verapamil can inhibit P-glycoprotein and CYP3A4 pathways affecting quinidine ...

Action

Avoid unless specialist-supervised. Use ECG and blood pressure monitoring if combination therapy is necessary.

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Quinidine and Verapamil together?

No — this combination should generally be avoided. Avoid unless specialist-supervised. Use ECG and blood pressure monitoring if combination therapy is necessary.

What is the severity of this interaction?

The interaction between Quinidine and Verapamil is classified as Major — avoid combination. Both drugs depress cardiac conduction, and verapamil can inhibit P-glycoprotein and CYP3A4 pathways affecting quinidine exposure, increasing risk of hypotension, bradycardia, and arrhythmias.

What should I do if I'm prescribed both?

Avoid unless specialist-supervised. Use ECG and blood pressure monitoring if combination therapy is necessary. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.